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<head>
  <meta charset="UTF-8">
  <meta http-equiv="X-UA-Compatible" content="IE=edge">
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  <title>Document</title>
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<body>
  <script>
    const arr = [10, 20, 30]
    // // 返回的符合条件的新数组
    // const res = arr.filter(function (item) {
    //   return item >= 20
    // })
    // console.log(res);

    const res = arr.filter(item => item >= 20)
    console.log(res);
  </script>
</body>

</html>